DUBLIN, Ireland & Madison, N.J.--(BUSINESS WIRE)--May 21, 2007
- Elan Corporation, plc (NYSE: ELN) and Wyeth Pharmaceuticals, a
division of Wyeth (NYSE: WYE), today announced the decision to
initiate a Phase 3 clinical program of their lead immunotherapeutic
candidate, Bapineuzumab (AAB-001), for the treatment of patients
with mild to moderate Alzheimer's Disease. This decision was based
on the seriousness of the disease and the totality of what the
companies have learned from their immunotherapy programs, including
a scheduled Interim look at data from an ongoing Phase 2 study,
which remains blinded. No conclusion about the Phase 2 study can be
drawn until the study is completed and the final data are analyzed
and released in 2008. Phase 3 clinical trial design will be
finalized with regulatory agencies, and subject to regulatory
approval, it is intended for the trial to begin in the second half
of 2007.

It is important to remember that Alzheimer's disease is a
complex and formidable challenge, and our immunotherapeutic
programs still contain inherent risks.

About Bapineuzumab

Bapineuzumab (AAB-001) is a humanized monoclonal antibody that
received Fast Track designation from the United States Food and
Drug Administration (FDA) for treatment of mild to moderate
Alzheimer's disease. Fast Track designation facilitates development
and may expedite regulatory review of drugs that the FDA recognizes
as potentially addressing an unmet medical need for serious or life
threatening conditions.

There are two ongoing Phase 2 studies with Bapineuzumab. The
first Phase 2 trial is a randomized, double-blind, placebo
controlled, multiple ascending dose study of 4 cohorts of the
approximately 240 total patients with mild to moderate Alzheimer's
disease. The primary objective of the trial is to assess the safety
of bapineuzumab. Assessments of cognitive and functional status are
also being made in the trail, and each patient's participation
lasts approximately 18 months. The key end-points include: ADAS-Cog
(assesses cognition), Neuropsychological Test Battery (NTB) and DAD
score (measures quality of life). The second Phase 2 trial is an
Alzheimer's beta-amyloid imaging study in 30 patients and is being
conducted in Europe. The companies do not expect that any Phase 2
data will be released into the public domain until the completion
of the Phase 2 trials in 2008.

About Alzheimer's Disease

Alzheimer's disease is a progressive brain disorder that
gradually destroys a person's memory and ability to learn, reason,
make judgments, communicate and carry out daily activities. As
Alzheimer's progresses, individuals may also experience changes in
personality and behavior, such as anxiety, suspiciousness or
agitation, as well as delusions or hallucinations. It is currently
estimated that more than 5 million Americans and more than 24
million people worldwide have Alzheimer's disease (Source:
Alzheimer's Association and Alzheimer's Disease International)

About the Elan and Wyeth Collaboration

The Elan and Wyeth Alzheimer's Immunotherapy Program (AIP) is a
50:50 collaboration to research, develop and commercialize an
immunotherapeutic approach that may be used for the treatment of
mild to moderate AD and possibly to prevent the onset of the
disease. Current AIP programs include bapineuzumab (AAB-001),
AAB-001 SubQ, ACC-001 and AAB-002. Wyeth and Elan equally share all
costs and potential revenues from this collaboration.

About Elan

Elan Corporation (NYSE: ELN), plc is a neuroscience-based
biotechnology company committed to making a difference in the lives
of patients and their families by dedicating itself to bringing
innovations in science to fill significant unmet medical needs that
continue to exist around the world. Elan shares trade on the New
York, London and Dublin Stock Exchanges. For additional information
about the company, please visit http://www.elan.com

Wyeth is one of the world's largest research-driven
pharmaceutical and health care products companies. It is a leader
in the discovery, development, manufacturing and marketing of
pharmaceuticals, vaccines, biotechnology products and
non-prescription medicines that improve the quality of life for
people worldwide. The Company's major divisions include Wyeth
Pharmaceuticals, Wyeth Consumer Healthcare and Fort Dodge Animal
Health. For additional information about the company, please visit
https://www.wyeth.com.

Safe Harbor / Forward-Looking Statements

The statements in this press release that are not historical
facts are forward-looking statements that involve risks and
uncertainties and include, without limitation, the risks associated
with the inherent uncertainty of the clinical development of
AAB-001 for Alzheimer's disease and whether AAB-001 will ever be
approved for commercialization. Factors which could cause actual
results to differ materially from the companies' current
expectations include the risks that problems or delays may arise
during preparations for the proposed Phase 3 trial or, if the
proposed Phase 3 trial is initiated, during the course of the Phase
3 trial, that the Phase 2 trials may not be successfully completed,
and even if the Phase 2 trials are successfully completed, that
results in the proposed Phase 3 trial may not show that AAB-001 is
safe and effective, as well as the other risks and uncertainties
described from time to time in the companies' periodic and other
reports filed with the Securities and Exchange Commission.